1. Field of the Invention
The invention relates to a method and apparatus for mechanised processing of vacuum-molded glass batches or lumps.
2. Description of the Prior Art
Glass lumps are taken from the melt by means of a one- or multi-part suction mold in accordance with the method described in German No. PS 21 61 885. Then, normally, the whole glass lump or batch is transferred to a blowing iron or lance. Further processing of the glass lump such as preliminary blowing, marving or final blowing in the mold takes place manually. To this end, the glass lump, which sticks to the blowing iron, must be transported between several work stations and must be safely controlled by the glassmaker at all times. With smaller glass lumps, this type of further processing work can only just be managed by a single glassmaker.
With glass lumps of greater weight however, approximately over 25 kg, a lump formed by vacuum molding is no longer manually treatable because it is too unstable due to its high heat content and cannot be adequately controlled by a single glassmaker. Nor can such vacuum molded glass lumps be properly managed with conventional aids such as hooks and lifting tackle successfully applied to glass lumps formed in the conventional way, such as by multiple (up to 7 times) overtapping, because the required processing conditions cannot be realised with such aids.
Compared with the conventional method of forming glass lumps, by multiple overtapping, i.e. covering or coating of a slightly cooled, solidified hollow glass sphere sticking to the blowing iron with a new layer of viscous glass, the vacuum holding method has considerable advantages as described in German No. PS 21 61 885. The conventional method is very heavy work and can be carried out only by physically very strong glassmakers of which, moreover, a large number (6 to 8 persons per work station) must be provided.